Lex (Michael Rosenbaum) faces the consequences of his shady dealings in Metropolis years ago when an old enemy comes to Smallville intent on destroying his life, ultimately putting Clark (Tom Welling) and Lana (Kristin Kreuk) in harm's way. Meanwhile, Clark has his hands full as he tries not only to protect Lex from the past, but also keep Chloe (Allison Mack) out of his after she discovers a mystery surrounding his adoption.